Title: Biodiversity: Importance and Measurement
Name: John Hammond
Date: 3/8/2010
Goals:
Students will:
1. Experience how diversity is important for ecosystem resilience
2. Learn about the benefits society gains from diverse ecosystems
3. Look at how we measure diversity in an effort to maintain and compare ecosystems
Objectives:
Students will:
1. Perform an activity about ecosystem interconnectedness using a web of yarn
2. Discuss the web nature of an ecosystem
3. Learn how genetic diversity allows an ecosystem to survive and rebound from disease and disasters using a tree role-playing activity
4. Perform an activity involving measurement of diversity
5. Use mathematical skills to fill out a table of relative abundances
6. Explore a diversity index using new mathematical concepts
Benchmarks:
Mathematics – Grade 6
Number and Operations
6.1.3 Use and analyze a variety of strategies, including models, for solving problems with multiplication and division of decimals.
6.1.4 Develop fluency with efficient procedures for multiplying and dividing fractions and decimals and justify why the procedures work.
6.1.5 Apply the inverse relationship between multiplication and division to make sense of procedures for multiplying and dividing fractions and justify why they work.
6.1.6 Apply the properties of operations to simplify calculations.
6.1.7 Use the relationship between common decimals and fractions to solve problems including problems involving measurement.
Number and Operations and Probability
6.2.1 Develop, analyze, and apply the meaning of ratio, rate, and percent to solve problems.
6.2.2 Determine decimal and percent equivalents for common fractions, including approximations.
Algebra
6.3.1 Use order of operations to simplify expressions that may include exponents and grouping symbols.
6.3.2 Develop the meanings and uses of variables.
6.3.3 Write, evaluate, and use expressions and formulas to solve problems.
6.3.4 Identify and represent equivalent expressions (e.g., different ways to see a pattern).
6.3.5 Represent, analyze, and determine relationships and patterns using tables, graphs, words and when possible, symbols.
6.3.6 Recognize that the solutions of an equation are the values of the variables that make the equation true.
6.3.7 Solve one-step equations by using number sense, properties of operations, and the idea of maintaining equality on both sides of an equation.
Mathematics – Grade 7
Number and Operations and Algebra
7.1.1 Develop, analyze, and apply models (including everyday contexts), strategies, and procedures to compute with integers, with an emphasis on negative integers.
7.1.2 Extend knowledge of integers and positive rational numbers to solve problems involving negative rational numbers.
Number and Operations, Algebra, and Geometry
7.2.1 Represent proportional relationships with coordinate graphs and tables, and identify unit rate as the slope of the related line.
7.2.3 Use coordinate graphs, tables, and equations to distinguish proportional relationships from other relationships, including inverse proportionality.
Mathematics – Grade 8
Data Analysis and Algebra
8.2.1 Organize and display data (e.g., histograms, box-and-whisker plots, scatter plots) to pose and answer questions; and justify the reasonableness of the choice of display.
8.2.2 Use measures of center and spread to summarize and compare data sets.
8.2.3 Interpret and analyze displays of data and descriptive statistics.
8.2.4 Compare descriptive statistics and evaluate how changes in data affect those statistics.
8.2.5 Describe the strengths and limitations of a particular statistical measure, and justify or critique its use in a given situation.
8.2.6 Use sample data to make predictions regarding a population.
8.2.7 Identify claims based on statistical data and evaluate the reasonableness of those claims.
Science – Grade 6
Interaction and Change
6.2L.2 Explain how individual organisms and populations in an ecosystem interact and how changes in populations are related to resources.
Scientific Inquiry
6.3S.1 Based on observation and science principles propose questions or hypotheses that can be examined through scientific investigation. Design and conduct an investigation that uses appropriate tools and techniques to collect relevant data.
6.3S.2 Organize and display relevant data, construct an evidence-based explanation of the results of an investigation, and communicate the conclusions.
6.3S.3 Explain why if more than one variable changes at the same time in an investigation, the outcome of the investigation may not be clearly attributable to any one variable.
Science – Grade 7
Interaction and Change
7.2L.2 Explain the processes by which plants and animals obtain energy and materials for growth and metabolism.
7.2E.1 Describe and evaluate the environmental and societal effects of obtaining, using, and managing waste of renewable and non-renewable resources.
7.2E.3 Evaluate natural processes and human activities that affect global environmental change and suggest and evaluate possible solutions to problems.
Scientific Inquiry
7.3S.1 Based on observations and science principles propose questions or hypotheses that can be examined through scientific investigation. Design and conduct a scientific investigation that uses appropriate tools and techniques to collect relevant data.
7.3S.2 Organize, display, and analyze relevant data, construct an evidence-based explanation of the results of an investigation, and communicate the conclusions including possible sources of error.
7.3S.3 Evaluate the validity of scientific explanations and conclusions based on the amount and quality of the evidence cited.
Science – Grade 8
Scientific Inquiry
8.3S.1 Based on observations and science principles propose questions or hypotheses that can be examined through scientific investigation. Design and conduct a scientific investigation that uses appropriate tools, techniques, independent and dependent variables, and controls to collect relevant data.
8.3S.2 Organize, display, and analyze relevant data, construct an evidence-based explanation of the results of a scientific investigation, and communicate the conclusions including possible sources of error. Suggest new investigations based on analysis of results.
Background Material:
Retrieved March 17, 2010 from
stalwiki.org/coastalwiki/Measurements_of_biodiversity
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Measurements of biodiversity
A variety of objective measures have been created in order to empirically measure biodiversity. The basic idea of a diversity index is to obtain a quantitative estimate of biological variability that can be used to compare biological entities, composed of direct components, in space or in time. It is important to distinguish ‘richness’ from ‘diversity’. Diversity usually implies a measure of both species number and ‘equitability’ (or ‘evenness’). Three types of indices can be distinguished:
1. Species richness indices: Species richness is a measure for the total number of the species in a community. However, complete inventories of all species present at a certain location, is an almost unattainable goal in practical applications.
A visualization of the species richness: with respectively 5 and 10 species.
2. Evenness indices: Evenness expresses how evenly the individuals in a community are distributed among the different species.
A visualization of the evenness of 5 species.
3. Taxonomic indices: These indices take into account the taxonomic relation between different organisms in a community. Taxonomic diversity, for example, reflects the average taxonomic distance between any two organisms, chosen at random from a sample. The distance can be seen as the length of the path connecting these two organisms along the branches of a phylogenetic tree.
These three types of indices can be used on different spatial [1]
· Alpha diversity refers to diversity within a particular area, community or ecosystem, and is usually measured by counting the number of taxa within the ecosystem (usually species level)
· Beta diversity is species diversity between ecosystems; this involves comparing the number of taxa that are unique to each of the ecosystems. For example, the diversity of mangroves versus the diversity of seagrass beds.
· Gamma diversity is a measure of the overall diversity for different ecosystems within a region. For example, the diversity of the coastal region of Gazi Bay in Kenia.
Diversity measurement is based on three assumptions
1. All species are equal: this means that richness measurement makes no distinctions amongst species and threat the species that are exceptionally abundant in the same way as those that are extremely rare species. The relative abundance of species in an assemblage is the only factor that determines its importance in a diversity measure.
2. All individuals are equal: this means that there is no distinction between the largest and the smallest individual, in practice however the smallest animals can often escape for example by sampling with nets.
Taxonomic and functional diversity measures, however, do not necessarily treat all species and individuals as equal.
3. Species abundance has been recorded in using appropriate and comparable units. It is clearly unwise to use different types of abundance measure, such as the number of individuals and the biomass, in the same investigation. Diversity estimates based on different units are not directly comparable.
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ipedia.org/wiki/Shannon-Wiener_index has a mathematical proof of evenness maximizing the Shannon index
Retrieved March 17, 2010 from balissues.org/article/170/why-is-biodiversity-important-who-cares
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Why is Biodiversity Important?
Biodiversity boosts ecosystem productivity where each species, no matter how small, all have an important role to play.
For example,
· A larger number of plant species means a greater variety of crops
· Greater species diversity ensures natural sustainability for all life forms
· Healthy ecosystems can better withstand and recover from a variety of disasters.
And so, while we dominate this planet, we still need to preserve the diversity in wildlife.
A healthy biodiversity offers many natural services
Ecosystems such as the Amazon rainforest are rich in diversity. Deforestation threatens many species such as the giant leaf frog, shown here. (Images source: Wikipedia)
A healthy biodiversity provides a number of natural services for everyone:
· Ecosystem services, such as
o Protection of water resources
o Soils formation and protection
o Nutrient storage and recycling
o Pollution breakdown and absorption
o Contribution to climate stability
o Maintenance of ecosystems
o Recovery from unpredictable events
· Biological resources, such as
o Food
o Medicinal resources and pharmaceutical drugs
o Wood products
o Ornamental plants
o Breeding stocks, population reservoirs
o Future resources
o Diversity in genes, species and ecosystems
· Social benefits, such as
o Research, education and monitoring
o Recreation and tourism
o Cultural values
That is quite a lot of services we get for free!
The cost of replacing these (if possible) would be extremely expensive. It therefore makes economic and development sense to move towards sustainability.
A report from Nature magazine also explains that genetic diversity helps to prevent the chances of extinction in the wild (and claims to have shown proof of this).
To prevent the well known and well documented problems of genetic defects caused by in-breeding, species need a variety of genes to ensure successful survival. Without this, the chances of extinction increases.
And as we start destroying, reducing and isolating habitats, the chances for interaction from species with a large gene pool decreases. Side Note?Unfortunately the original link to the Nature.com article no longer works, since their site redesign, and I had not noted the publication details. However, for similar information, you could look at Consequences of changing biodiversity, Nature 405, 234 - 242, 11 May 2000 and Causes, consequences and ethics of biodiversity, Nature 405, 208–211, 11 May 2000.
Species depend on each other
While there might be “survival of the fittest” within a given species, each species depends on the services provided by other species to ensure survival. It is a type of cooperation based on mutual survival and is often what a “balanced ecosystem” refers to.
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Retrieved March 17, 2010 from ipedia.org/wiki/Biodiversity
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"Biological diversity" or "biodiversity" can have many interpretations and it is most commonly used to replace the more clearly defined and long established terms, species diversity and species richness. Biologists most often define biodiversity as the "totality of genes, species, and ecosystems of a region". An advantage of this definition is that it seems to describe most circumstances and present a unified view of the traditional three levels at which biological variety has been identified:
· species diversity
· ecosystem diversity
· morphological diversity
· genetic diversity
But Professor Anthony Campbell at Cardiff University, UK and the Darwin Centre, Pembrokeshire, has defined a fourth, and critical one: Molecular Diversity (see Campbell, AK J Applied Ecology 2003,40,193-203; Save those molecules: molecular biodiversity and life).
This multilevel conception is consistent with the early use of "biological diversity" in Washington, D.C. and international conservation organizations in the late 1960s through 1970's, by Raymond F. Dasmann who apparently coined the term and Thomas E. Lovejoy who later introduced it to the wider conservation and science communities. An explicit definition consistent with this interpretation was first given in a paper by Bruce A. Wilcox commissioned by the International Union for the Conservation of Nature and Natural Resources (IUCN) for the 1982 World National Parks Conference in Bali. The definition Wilcox gave is "Biological diversity is the variety of life forms...at all levels of biological systems (i.e., molecular, organismic, population, species and ecosystem)..." Subsequently, the 1992 United Nations Earth Summit in Rio de Janeiro defined "biological diversity" as "the variability among living organisms from all sources, including, 'inter alia', terrestrial, marine, and other aquatic ecosystems, and the ecological complexes of which they are part: this includes diversity within species, between species and of ecosystems". This is, in fact, the closest thing to a single legally accepted definition of biodiversity, since it is the definition adopted by the United Nations Convention on Biological Diversity.
The current textbook definition of "biodiversity" is "variation of life at all levels of biological organization".
For geneticists, biodiversity is the diversity of genes and organisms. They study processes such as mutations, gene exchanges, and genome dynamics that occur at the DNA level and generate evolution. Consistent with this, along with the above definition the Wilcox paper stated "genes are the ultimate source of biological organization at all levels of biological systems..."
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Selection bias amongst researchers may contribute to biased empirical research for modern estimates of biodiversity. In 1768 Rev. Gilbert White succinctly observed of his Selborne, Hampshire "all nature is so full, that that district produces the most variety which is the most examined."
Nevertheless, biodiversity is not distributed evenly on Earth. It is consistently richer in the tropics and in other localized regions such as the Cape Floristic Province. As one approaches polar regions one generally finds fewer species. Flora and fauna diversity depends on climate, altitude, soils and the presence of other species. In the year 2006 large numbers of the Earth's species were formally classified as rare or endangered or threatened species; moreover, many scientists have estimated that there are millions more species actually endangered which have not yet been formally recognized. About 40 percent of the 40,177 species assessed using the IUCN Red List criteria, are now listed as threatened species with extinction - a total of 16,119 species.